The overall objective of this project is to understand the role of serum hormone binding proteins in normal physiology and in the pathophysiology of various human disease states. Novel methods which improved precision and sensitivity for the measurement of the principal human sex hormone transport proteins, testosterone-estradiol binding globulin and albumin, have been developed. Future directions of the project include the development and characterization of an animal model in which the physiologic role of the steroid binding globulins can be investigated and a detailed assessment of the nature of sex steroid transport throughout human development with particular emphasis on puberty and its disorders.